Electronic drums have been in use for several years now, and the technology is fairly straight forward. Put simply, a piezo electronic element generates a small but detectable current when the element is vibrated. These piezo elements are embedded into pads, cymbals or tubes, and the electrical output is routed to signal processors, commonly referred to as drum modules or “brains.” Each piezo signal is assigned a sound by the drummer, through the programming function of the drum module. If a particular pad is assigned a snare drum sound, for example, a sound pattern is artificially generated by the drum module when electrical inputs from the pad are detected, and these sounds are routed out of the module for amplification. Literally hundreds of different sound patterns can be generated, and a typical drum set uses from 5 to 50 sounds, depending upon the sophistication of the drum set.
The high-hat instrument presents unique problems when it comes to generating an artificial sound pattern. The instrument that is simulated has two cymbals, one suspended over the other, as shown in FIG. 1. The upper cymbal 101 is suspended on a rod 103, and is spring-loaded up and away from the lower cymbal 102. A foot pedal 104, connected to the rod 103, is used to bring them together. The instrument makes a wide variety of sounds, depending upon the pressure exerted upon the pedal, the proximity of the cymbals, and the force with which the cymbal is struck. The instrument also makes a variety of sounds without striking; just pressing down with the foot brings the cymbals together, and makes a “chick” sound.
FIG. 2 shows a typical electronic high-hat arrangement that attempts to reproduce the sounds from the instrument depicted in FIG. 1. In order to simulate this instrument electronically, two inputs are needed; the position of the foot pedal 109 and the piezo signal from the impact sensitive electronic cymbal 108. The foot pedal 109 position is usually expressed to the drum module 106 through a voltage change that correlates to the pedal position. Typically, a constant voltage is sent to the pedal. Resistors come into play as the pedal is depressed. The altered voltage is sent back to the drum module, and the module detects the difference in the voltage. In some cases, a potentiometer is used to vary the voltage of the positional signal as the pedal is raised or lowered. Both the cymbal and the pedal are connected to the module using electrical cables 107, 105. A corresponding sound is generated in the drum module 106 based upon these two inputs. Note that there is no rod connecting the pedal to the high-hat cymbal.
As more bass drum notes became desirable in modern music, a second bass drum pedal was introduced, enabling drummers to play bass drum notes with both feet. Unfortunately, this requires drummers to take their foot off of the high-hat instrument, which leaves the upper cymbal suspended above the lower one in acoustic drum sets. To make matters worse, metal high-hat cymbals are generally very thick and produce an unpleasant “clanging” noise when they are struck without contacting their paired lower cymbal. Therefore, removing the foot from the high-hat generally renders the instrument un-playable, and most drummers immediately switch to a ride cymbal even though a high-hat sound is desired.
FIG. 1 shows a conventional acoustic high-hat in the at-rest position, which is achieved using a lifting spring. Pedal 104 is fully raised and attached to rod 103 and that cymbal 101 which is also attached to rod 103 is thereby also fully raised. Note the undesirable gap between cymbals 101 and 102.
In FIG. 1a, the pedal 104a has been depressed, the paired cymbals 101a and 102a have been drawn together, and the high-hat is ready for playing.
There are a few inventions on the market that attempt to make the acoustic high-hat playable when the foot is removed, and they usually involve a locking device that holds the pedal down when the foot is pulled away. When the locking device is disabled, the hi hat works normally again. The problem is that levers must be manipulated while trying to play the drums in order to lock or unlock a mechanical clutch, and it is sometimes difficult to consistently get the correct pedal pressure. Most drummers simply abandon the high-hat instrument rather than work the clutch mechanism. There are also devices that use light beams to sense when the drummer's foot has left the pedal, and an electromagnetic solenoid is activated to physically move the pedal to a preset position. These devices are expensive and complex, not suitable for most electronic high-hat control pedals, and are rarely used.
Unfortunately, prior art electronic high-hat devices have mimicked the conventional high-hat instrument all too well. When the foot leaves the instrument, this same irritating clanging noise is generated by electronic high-hats, and the instrument is generally abandoned when a second bass drum pedal is used.